[Ffmpeg-devel-irc] ffmpeg.log.20120914

[burek]

[00:00] <JEEB> 'the h.264 advanced video compression standard pdf' as google keywords should bring you good fortune :)
[00:00] <JEEB> I have that book around myself as well :)
[00:00] <JEEB> also, if you really have no idea about things to begin with
[00:01] <JEEB> http://www.xiph.org/video/vid1.shtml
[00:01] <JEEB> this is a short'ish video lecture on digital video and audio
[00:01] <Protonsoup> ooo a video
[00:01] <JEEB> monty's a man <3
[00:01] <JEEB> because of him I'm thinking of holding a lecture on basics of video compression using libavcodec
[00:02] <Protonsoup> "i'd like to address the mathematicians" i'm liking this video already
[00:03] <JEEB> also, I wrote my first video encoder into libavcodec this year :)
[00:03] <Protonsoup> nice
[00:08] <llogan> JEEB: which one was that?
[00:09] <JEEB> ut video
[00:09] Action: llogan likes ut video
[00:09] <JEEB> http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=1ab5a780424ae8755858e153def1173a50a44e4c
[00:09] <JEEB> :)
[00:10] <llogan> ah. i remember seeing that. nice.
[00:10] <JEEB> also I fixed the decoder :)
[00:10] <JEEB> my mentor had left a brainderp in the code
[00:11] <JEEB> http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=01cb4c84f54a52725c9b4b4dd6c609c36cccc5d4
[00:13] <llogan> any differences with your implementation compared to the library?
[00:14] <JEEB> encoder? it should be rather similar but only uses one symbol so far and thus gives a wee bit better compression. Not much assembly in it tho. Also one day I'll have to find time to multithread it :)
[00:14] <JEEB> might have a wee bit better compression
[00:15] <JEEB> in general
[00:15] <JEEB> I think I tested it with multiple slices against the reference one
[00:17] <JEEB> oh, and the only feature it lacks is interlaced encoding, but to be honest -- I don't know if that would be worth it
[00:20] <Protonsoup> what's the best video format to use for SD live-action content using the flv container?
[00:20] <Protonsoup> mp4?
[00:20] <llogan> mp4 is another container
[00:20] <Protonsoup> oh
[00:20] <JEEB> H.264
[00:20] <JEEB> naturally
[00:20] <Protonsoup> for SD?
[00:20] <JEEB> yes, for /everything/
[00:20] <JEEB> whatever the resolution, H.264 beats all
[00:20] <Protonsoup> ah ok
[00:21] <JEEB> also the list of supported audio/video formats for flv is rather short so it's not even a hard choice in this case because you literally don't have one
[00:21] <Protonsoup> heh okay
[00:21] <JEEB> other formats available are IIRC sorenson spark, vp3, vp62
[00:22] <Protonsoup> is there any format you recommend for animated video?
[00:22] <JEEB> still the same as always
[00:22] <Protonsoup> ok
[00:22] <JEEB> thanks to b-frames and all, it's a clear winner
[00:23] <JEEB> x264 and H.264 are something people play with to create floppy-sized encodes and all
[00:23] <JEEB> and where actually the audio becomes more of a problem
[00:23] <Protonsoup> is x264 and H.264 different?
[00:23] <JEEB> no
[00:24] <JEEB> x264 is just the best H.264 encoder around
[00:24] <Protonsoup> ah
[00:24] <Protonsoup> x264 is a software while H264 is a technique?
[00:24] <JEEB> H.264 is a standard, and x264 is a piece of software that implements it
[00:24] <Protonsoup> ah
[00:25] <llogan> wiki articles should clarify your basic questions on the differences
[00:25] <JEEB> with H.264 it's also a bit-exact format
[00:25] <JEEB> so all decoders should give exactly the same output for the same encoded bit stream
[00:25] <llogan> s/on the differences//
[00:25] <Protonsoup> ah
[00:25] <JEEB> I did link him the specification and multimediawiki as well :)
[00:26] <JEEB> and the google keyword 'the h.264 advanced video compression standard pdf'
[00:26] <JEEB> for a more book-like ride into H.264
[00:26] <Protonsoup> yes you did. thanks
[00:26] <JEEB> and by H.264, pretty much all of the common tricks in video encoding for now :)
[00:27] <JEEB> HEVC really just makes the macroblocks even more bigger
[00:27] <JEEB> and adds some other things
[00:27] <Protonsoup> i had an episode of Community, in avi format, i just converted it to x264 (flv) and vp8(webM) and the file size difference is huge
[00:28] <Protonsoup> almost half the size with x264
[00:28] <JEEB> sounds like you used different settings
[00:28] <JEEB> the default for x264 is -crf 23
[00:28] <JEEB> while vp8 probably has some bitrate set
[00:28] <Protonsoup> ah
[00:29] <JEEB> x264 is really "is this really /this/ easy to use?" level
[00:29] <Protonsoup> haha
[00:29] <JEEB> 1) encode a few thousand frames of something with various crf values, and pick the highest that still looks good
[00:29] <Protonsoup> so what you're saying is, convert my entire collection into x264
[00:29] <JEEB> 2) check out the -preset presets
[00:30] <JEEB> 3) pick the slowest preset that is still fast enough for your needs
[00:30] <JEEB> 4) possibly bandwidth limitations to keep the stream viewable over a certain connection speed with -maxrate and -bufsize
[00:30] <JEEB> 5) ???
[00:30] <JEEB> 6) profit!
[00:30] <Protonsoup> is there a way i can get a list of all presets?
[00:30] <JEEB> http://mewiki.project357.com/wiki/X264_Settings#preset
[00:30] <JEEB> medium is default with x264
[00:31] <Protonsoup> does ffmpeg use the same presets when encoding to x264?
[00:31] <JEEB> yes, it just passes the preset to the library
[00:31] <Protonsoup> cool
[00:31] <JEEB> when you use -preset
[00:31] <JEEB> that's why there are no external ffpreset files
[00:32] <JEEB> and from the x264.h header: "Warning: the speed of these presets scales dramatically.  Ultrafast is a full 100 times faster than placebo!"
[00:33] <JEEB> basically everything but ultrafast and placebo are "generally usable"
[00:33] <JEEB> naturally the slower you go the more compression-related stuff can be enabled
[00:35] <JEEB> <Protonsoup> so what you're saying is, convert my entire collection into x264 <- if you need to encode /everything/ , sure. But I usually leave old stuff be; I can always grab the source and re-encode if I really want to
[00:37] <Protonsoup> are b-frames a patented technology?
[00:37] <JEEB> my dear, /everything/ and their dog are patented
[00:38] <Protonsoup> lol i mean, if vp8 wanted to implement b-frames, do they have to pay for it?
[00:38] <JEEB> VLC (variable length coding), for example, is just a fancy and patented way of saying "Huffman Encoding"
[00:38] <JEEB> (this is used in H.264 as CAVLC)
[00:39] <Protonsoup> ok
[00:40] <JEEB> I don't think they'd have to pay for the implementation of b-frames, but it might make them a more viable target for people to actually want to use their patents
[00:40] <JEEB> I wonder if anyone remembers how MS released their VC-1 format royalty free?
[00:40] <JEEB> and how it quite quickly became one of those formats you can now get a license for via MPEG-LA :)
[00:41] <Protonsoup> Sorry, i dont know about that.
[00:42] <JEEB> VP8 would most probably get a similar fate if it was A) actually compelling compression-wise and B) if it had similar uses to VC-1 (VC-1 got onto both blu-ray and hd-dvd standards)
[01:10] <cjeffries_> anyone know what the correct filter names are for the rear channels of a 7.1 layout are?
[01:22] <itsrachelfish> hey #ffmpeg!
[01:37] <llogan> cjeffries_: RL RC RR?
[02:34] <cjeffries_> llogan: i tried that and I kept getting messages that said "No such filter: '6.0-RL'.  Honestly I couldn't find where to reference what was a good filter, I just adapted the example for 5.1 in the documentation to try and fit 7.1
[05:05] <itsrachelfish> I'm using ffmpeg to save videos from my webcam, is there any way to view the video as it's being saved?
[07:00] <itsrachelfish> WAT
[08:32] <newenc> can anyone explain this '-map 0:7 -map_channel 0.7.0 -map_channel 0.7.1'
[12:03] <ctwiz> When converting an mov from iMovie to gif, is there any way I can improve the picture quality? The colors get distorted, and there are a ton of artifacts.
[12:06] <relaxed> ctwiz: you want iMovie support here?
[12:06] <ctwiz> no, the iMovie .mov file looks fine
[12:06] <ctwiz> even when converted to image%d.jpg the images still look fine
[12:07] <relaxed> Oh, ffmpeg's .gif encoder has always been mediocre at best.
[12:07] <ctwiz> it's when I'm converting to gif that it gets pretty distorted. I was just wondering if there were more settings to help improve upon the basic `ffmpeg -i clip.mov -pix_fmt rgb24 test.gif'
[12:08] <ctwiz> relaxed: hm. can you recommend something else?
[12:09] <relaxed> ctwiz: Yes, output the frames you want with ffmpeg and use imagemagick's convert to create the gif.
[12:09] <ctwiz> That's a great idea. I appreciate it. I'll test it out now. Thanks, relaxed. :)
[12:09] <relaxed> I think gimp can create gis too
[12:09] <relaxed> gifs*
[12:13] <ctwiz> does gimp have a cli?
[12:13] <ctwiz> I did not know that.
[12:14] <relaxed> Not that I'm aware of.
[12:14] <relaxed> For cli convert is the way to go.
[12:16] <ctwiz> alright, sweet.
[12:48] <Yexo> I'm pretty sure gimp can convert via cli
[13:17] <smj> so, when is ffmpeg going to encode Opus?
[13:20] <Peace-> hi i have frei0r compiled and all ffmpeg works with them but i am unable to find some nice documentation to use frei0r with ffmepg
[13:21] <Peace-> i used ffmepg docuemntation and i tried to go on frei0r website
[13:21] <Peace-> but ... :S i can't find everything some base example
[13:21] <Peace-> yes
[13:44] <ctwiz> relaxed: thanks again for the help earlier.
[13:44] <ctwiz> night all.
[18:09] <brimestone> hry guys, need help with compiling FFmpeg on OSX 10.7.x i get this error http://pastebin.com/jx2CtGBx
[18:45] <brimestone> OMG!! i'm so annoyed by the new Xcode in mac. apparently, its not enough to install xcode to get the command line tools needed to compile stuffs.. but you have to go to the app>preferrence>download then specifically install "commandl line tools"
[18:46] <penyulap> I have a very nice command I use quite a lot, it's " ffmpeg  -i %04d.png  -vcodec mjpeg -sameq test.avi " but this time the images aren't called 001.png 002.png 003.png they are called freame9964.jpg and that is where they start, how can I tell ffmpeg to look for the prefix, and start at 9964 ? and is jpg Ok ?
[18:47] <brimestone> ??
[18:47] <penyulap> !!
[18:50] <relaxed> penyulap: cat *jpg | ffmpeg -f image2pipe -vcodec mjpeg -i - -qscale 3 test.avi
[18:51] <saste> penyulap, check an updated ffmpeg, there is -start_from option in image2 demuxer
[18:51] <penyulap> oooh cool
[18:51] <penyulap> i should update?
[18:51] <penyulap> wait i try this new shiny command line :)
[18:51] <saste> penyulap, yes it's fairly new, it's been committed since a couple weeks
[18:52] <saste> also there is a glob pattern option, check the docs for more
[18:52] <penyulap> oh
[18:52] <saste> (all new stuff, so you need a recent ffmpeg)
[18:54] <relaxed> er, that should have been:  cat *jpg | ffmpeg -f image2pipe -vcodec mjpeg -i - -vcodec copy test.avi
[18:54] <relaxed> you probably want to specify the input framerate with -r $fps
[18:55] <penyulap> argh! I have a whole lot of blender in the "(Neo) Woah ... I know jujitsu" pipe into my bwain at the moment, I wants to learn it all, one thesis at a time :D
[18:55] <penyulap> linux is madness :D :D
[18:56] <penyulap> I loves
[18:59] <penyulap> it worked, but my goodness it looks blah. It's at a resolution of 160x 107 pixels. originals were 640 x 426 pixels
[19:00] <penyulap> it had an error code as it ran too
[19:00] <penyulap> it said
[19:00] <penyulap> mjpeg @ 0x88852b0]mjpeg: error, decode_app parser read over the end
[19:01] <penyulap> something else max analyse duration reached
[19:01] <penyulap> and estimating duration from bitrate, this may be inaccurate
[19:02] <penyulap> im not sure i can do anything but type the whole lot, because it is a different machine
[19:04] <penyulap> wait i can do that
[19:05] <penyulap> pastie.org/4720962
[19:05] <penyulap> i dids it
[19:07] <penyulap> each image is a 640 x 426 pixel JPEG Image of 50.2 KB
[19:07] <relaxed> penyulap: cat *jpg | ffmpeg -f image2pipe -s 640:426 -r 25 -vcodec mjpeg -i - -vcodec copy test.avi
[19:07] <brimestone> what am i loosing from disabling yasm?
[19:08] <Mavrik_> boatload of performance :)
[19:08] <brimestone> damn.. so i should turn it on then
[19:08] <jeffq> Hey, I'm having some trouble compiling ffmpeg for ARM. Looking at the config.log, it looks like all of the floating point tests fail because the soft floating point functions aren't being linked into the tests (I'm getting stuff like ffconf.aZ3y8kXB.c:(.text+0x10): undefined reference to `__aeabi_f2d') for all of the config tests. Because of this things like HAVE_ISNAN aren't defined and it won't compile. Any ideas :)?
[19:08] <relaxed> brimestone: just install yasm
[19:09] Action: brimestone trying to figure out how to install yasm on OSX 10.7.4
[19:10] <penyulap> zomg vlc goes insane like i have never seen before.
[19:11] <relaxed> jeffq: Go to http://fate.ffmpeg.org/ and click on the far right link of the arch you're targeting and you might see some useful tips.
[19:12] <penyulap> when vlc plays, vlc changes its size about twice per second, changing the size of its window, flashing back and forth from small to large as it goes through the 44 second count, the vid would last about that long if it worked.
[19:13] <jeffq> ah, this looks promising. thanks!
[19:14] <penyulap> it says you can paste a reply, so i pasted a reply.pastie.org/4721009
[19:17] <relaxed> penyulap: Maybe piping it isn't the way to go. If you have a 64bit system you can try my static build and see if saste's suggestion about using -start_from. http://goo.gl/DPrRY
[19:17] <penyulap> i have a simple system, its ok, i will make do
[19:18] <penyulap> i will try to find another way, thank you sincerely for the assistance though
[19:20] <relaxed> penyulap: http://ffmpeg.org/faq.html#How-do-I-encode-single-pictures-into-movies_003f  (rename the sequence)
[19:21] <penyulap> i will have a look, thank you so much
[19:21] <jeffq> FYI the problem was that I wasn't passing -mfloat-abi=softfp in -extra-cflags, just directly to GCC in case anyone ever has the same problem
[19:22] <penyulap> i'm not sure how to do such monumental renaming, there are a LOT of files you see.
[19:23] <brimestone> the version of yasm currently on the git server doesnt have the "configure" file..
[19:54] Action: brimestone re-compile ffmpeg with --enable yasm
[20:31] <brimestone> finally.. i got both FFmpeg and FFmbc to compile with Yasm
[20:32] <llogan> brimestone: did you figure out the gcc issue from yesterday?
[20:32] <brimestone> yes?
[20:32] <llogan> maybe i should ask: what was the problem and how did you fix it?
[20:33] <brimestone> it was xCode not completly installed.. then after that i have to install "Commmand Line Tools" via the Preferrence pane in Xcode
[20:33] <llogan> because i forget how literal people are
[20:33] <llogan> you are using Lion?
[20:33] <brimestone> yes.. then complication with xCode since i was running 10.7.2 to match with my Avids
[20:34] <llogan> so that "use clang instead of gcc" statement was not true in your case?
[20:34] <brimestone> so i had to upgrade to 10.7.4, install xCode completely, then open xCode and install "Command Line Tools" via the Preference pane in xCode under "downloads tab"
[20:34] <brimestone> clang would do nothing
[20:35] <brimestone> then i installed yasm via homebrew
[20:35] <brimestone> http://tedsimbajon.com/Blog/TechBlogExploded.php?id=76
[20:35] <brimestone> i make a note for me, so i wont forget
[20:35] <llogan> feel free to update that guide i linked to yesterday if you like. i'd prefer it to be cleaner and more accurate
[20:36] <brimestone> where?
[20:36] <llogan> https://ffmpeg.org/trac/ffmpeg/wiki/MacOSXCompilationGuide
[20:36] <brimestone> ?? how am i going to update that?
[20:36] <llogan> i'd do it, and make it more step-by-step like the Ubuntu and CentOS guides, but i have no Apple computer
[20:36] <llogan> create an account and edit it like any other wiki
[20:36] <brimestone> ohhh? i can help you with that..
[20:37] <brimestone> ohh really? let me create an account..
[20:37] <llogan> https://ffmpeg.org/trac/ffmpeg/register
[20:37] <llogan> here's a more complete example: https://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuide
[20:38] <brimestone> llogan, are you like a developer for ffmpeg?
[20:39] <llogan> i contribute on occasion. im not a coder, but i mostly deal with the mailing lists..which reminds me i have to deal with the mailing lists...
[20:39] <brimestone> wow.. well.. i'd like to say, Thank you..
[20:41] <brimestone> verification email ain't coming in..
[20:43] <llogan> maybe it's slow. let me know if it doesn't arrive in 10 minutes
[20:44] <llogan> ffmpeg and ffmbc share many of the same files. how does it allow you to install both without conflict?
[20:45] <llogan> i install both by adding incdir, libdir, shlibdir with appropriate paths to ffmbc configure
[20:56] <brimestone> hmmn wiki doesnt have richText plugin?
[20:57] <brimestone> let me write this on my wiki and paste it back
[20:58] <rfmx49> ffmpeg newbie here, when using ffmpeg -i file.wav file.mp3 When playing file.mp3 i get only static? what am i doing wrong?
[20:59] <rfmx49> Sorry scratch that it does work, issues with my media player. Thanks.
[21:10] <llogan> brimestone: formatting examples: https://ffmpeg.org/trac/ffmpeg/wiki/WikiFormatting
[21:12] <brimestone> there you go llogan.. i submitted it
[21:13] <brimestone> yup..i got use to my Wiki  here at work.. i have RichText Plugin.. makes it more easier to write technical stuff ( you dont have to think about formating)
[21:17] <llogan> ok. thanks for the update.
[21:19] <brimestone> wow!! i get 11 FPS now.. yesterday,i only get 7
[21:20] <brimestone> but still not realtime..
[21:21] <brimestone> huh?
[21:21] <llogan> i wanted to see your command to see if there was anything to suggest if you want a faster encode
[21:22] <brimestone> ohhh standby
[21:22] <brimestone> http://pastie.org/4721665
[21:23] <brimestone> WOW pastie kicks pastebin's butt
[21:30] <brimestone> llogan, did you see it?
[21:31] <llogan> brimestone: yes. i don't see anything obvious.
[21:39] <brimestone> hmmm if i can only get it to a least realtime
[21:39] <brimestone> hu hu hu hu hu
[21:41] <fredio> I want to cut an *.mp4 file. Is it "safe" to do it with ffmpeg with "-ss 20" "-t 3600" and "-acodec copy" and "-vcodec copy" or is this not a good way?
[21:42] <ubitux> you can try, i personally have some a/v sync trouble generally
[21:44] <fredio> so -vcodec copy do not change the video in any way?
[21:44] <llogan> brimestone: why dnxhd?
[21:45] <cbsrobot-> llogan: that's avid's nativ codec
[21:45] <fredio> I need to do it under windows, I tried to split a *.mp4 with mmg.exe works fine even with a/v sync, but the split ones have no preview anymore.
[21:51] <fredio> ok, first try to split. But the first seconds are black now in the new File.
[21:55] <llogan> in what player?
[21:56] <cbsrobot-> and
[21:56] <fredio> vlc
[21:58] <fredio> Here is the pastie http://pastebin.com/zyxZf0Dv from the split.
[22:03] <fredio> ah got it. In the new video file, the video length is 1min 24s but the audio length is 1min 29s. OK, now I know why the video is black the first 5s, but why is the Audio longer?
[22:14] <fredio> The problem lays deeper, even in the recorded source audio/video length differ. The ffmpeg cli which I use to record from an TV Card looks like:   http://pastebin.com/87xEakAP  Am I doing something wrong?
[23:33] <brimestone> well, cuz i work in a facility that has 40 Avid Suites on a Unity?
[23:33] <brimestone> so to re-wrap it with DNxHD is an easier workflow for us
[00:00] --- Sat Sep 15 2012